The development of space resources, particularly the comparatively abundant platinum group metals measured in the meteorite population and anticipated to be in the Near Earth Asteroid Population, require an unprecedented scale of space transportation in order to bring these valuable and useful materials to a terrestrial market.
Humankind has delivered payloads to space and returned them safely back through atmospheric re-entry over the last 50 years using technology such as capsules, lifting bodies, and most recently testing of inflatable aeroshells. This conventional technique of containerized protection is inefficient, leaving unusable scar mass that is a significant percentage of the returned system.
Low areal density metallic structures have been used in numerous space-based applications. For example, open-celled metal foams, primarily aluminum and copper, have been used over the past 40 years in an array of terrestrial applications related to heat exchange, energy absorption and flow diffusion. High production costs have limited the use of the material to advanced technology and aerospace applications, including electronics cooling, cryogen tanks, and phase change material heat exchangers. Over the past two decades, metal foams have been implemented in the space environment for shielding against meteorite impacts and have been considered for space-based application including large space mirror substrates, foam core for composite sandwich structures, planetary rover wheels, and porous storage vessels for propellant, cryogenic fluids, and superfluids.
However, to date, there has been little or no work in the creation of, for example, low areal density metallic structures in the space environment and delivery to earth.